Begun in 1961, the Apollo program became the backbone of the
American space program. Two significant highlights during the Apollo program
were the first humans to leave Earth orbit and the first human landing
on the Moon.
Many people feel that the Apollo program stands as mankind's greatest
technological achievement. In all, six missions landed on the surface of
the moon, and three others orbited the moon without landing, including
the ill-fated Apollo 13.
The Apollo program included a large number of uncrewed test missions
and 11 crewed missions. The 11 crewed missions include two Earth orbiting
missions, two lunar orbiting missions, a lunar swingby, and six Moon landing